Closure device and sack employing it

ABSTRACT

The present invention relates in particular to a closure device comprising:
         two substrate webs ( 12, 13 );   complementary closure means ( 2, 3 ), each being respectively connected to a corresponding web ( 12, 13 ),   characterized by the fact that each web ( 12, 13 ) consists of two parts, to with a first part ( 14, 16 ) bearing one of the closure means ( 2; 3 ), and a second part ( 15, 17 ) distinct from the first, these first ( 14, 16 ) and second ( 15, 17 ) parts being provided along their lower edge and upper edge respectively with mutual and complementary cooperation means ( 40, 41, 40′, 41 ′), such as clipping means.

The present invention relates to the field of closure devices comprising complementary closure means.

In certain cases, these means are actuated, respectively during opening and during closing, by a slide.

By way of a non-limiting example, such closure devices are an integral part of sacks.

These sacks comprise two generally parallel webs forming their main walls, complementary closure means built into the webs and possibly a slide for actuating said means, during closing and during opening.

During manufacture of these sacks, there are two zones for each web which have very different technical and mechanical characteristics.

The first is that which bears closure means such as profiles. It is generally provided with ribs or other protruding members.

The second consists of webs which subsequently delimit either a part of the closure or the walls of the sack. When a large size sack is involved, for example one intended to receive a considerable quantity of animal feed, this second zone has a vast extent.

During manufacture of these webs, particularly by profile, creep problems are observed in this second zone, which can have deleterious effects on the quality of the final product, particularly by bringing about deformations of the first zone, called the “technical zone.”

Moreover, it may be required or desired, for manufacturing reasons connected with the technical constraints specific to each zone of the closure devices and/or of the sack, that these sacks be made of distinct plastics which are incompatible or compatible in co- profile only with difficulty.

The present invention has as its principal object to remedy this difficulty, by providing a closure device structure that does not have these disadvantages.

The present invention therefore relates to a closure device comprising:

-   -   two substrate webs;     -   complementary closure means, each being respectively connected         to a corresponding web         -   characterized by the fact that each web consists of two             parts, to with a first part which bears one of the closure             means, and a second part distinct from the first, these             first and second parts being provided with mutual and             complementary cooperation means, such as clipping means.

Advantageously, the second parts of said webs are distinct entities.

However, according to another possible embodiment, the second parts of said webs consist of one and the same sheet folded over itself.

According to one advantageous embodiment, said closure means are molded integrally with the corresponding first part.

Said closure means can, however, consist of inserts.

Preferentially, said closure means are complementary profiles.

Advantageously, the mutual cooperation means are made up of complementary beads and gutters.

Finally, according to one variation, said first and second parts are made of different plastics, incompatible in profile.

The invention also relates to a sack manufactured making use of a device conforming to one of the foregoing embodiments.

According to the advantageous and non-limiting features of this sack:

-   -   said second parts of said webs themselves delimit the receptacle         of this sack,     -   it includes at least one additional web, attached to said first         parts and/or second parts, which delimits the receptacle of the         sack.

Other features and advantages of the present invention will appear upon reading the detailed description that follows, of a preferred embodiment.

This description will be given with reference to the appended drawing wherein:

FIG. 1 is a schematic section view of a closure device according to the invention.

FIG. 2 is a view similar to the foregoing of a variation in implementation of this device.

FIGS. 3 and 4 are very schematic section views of sacks which incorporate the closure device of FIG. 1.

FIG. 5A is a schematic view which shows the initially distinct elements of a closure device conforming to a variation of the present invention, designed to be assembled together to constitute a closure device including an opening indicator as shown schematically in section in FIG. 5B.

FIGS. 6, 7 and 8 are schematic views of three other embodiments of a sachet incorporating the closure device.

This description applies to a closure device which is subsequently used to manufacture a sack. It is, however, a simple example, the closure device being suitable for other uses, for example for uniting the two ends of a sheet designed to serve as a poster.

The closure device 1 shown in FIG. 1 has a structure generally known per se in outline. Its embodiment according to the invention, however, is innovative.

It has an upper part 10 and a lower part 11.

It consists of two webs made of plastic, labeled 12 and 13.

At the upper part 10, the two webs 12 and 13 are equipped with complementary closure profiles 2 and 3.

These profiles can be the subject of many embodiments. The invention is not limited to the exact embodiment illustrated in FIG. 1.

In the case illustrated here, the profiles 2 and 3 are respectively of the male and female type, as is well known to the person skilled in the art. The invention can, however, apply to other types of profiles, particularly those with complementary hooks. It can also apply to other closure means, such as those with loops and hooks, well known under the name of Velcro (trademark) strips.

In the implementation form of FIG. 1, the profiles 2 and 3 are extruded integrally with the webs 12 and 13.

However, in one variation of implementation not shown, these complementary profiles could be carried on support strips applied to the webs 12 and 13, for example by heat welding or adhesive bonding.

This device has the special features described hereafter.

In practice, the webs 12 and 13 each consist of two parts, to with a first part which bears one of the profiles, and a second part distinct from the first, these first and second parts being provided with mutual and complementary means of cooperation 4, such as clipping means.

More precisely, the web 12 includes a first part 14 (which can be called the upper part when considering FIG. 1) which bears the profile 2, while the web 13 includes a first part 16 which bears the profile 3.

Further, the web 12 includes a second part 15, while the web 13 has an analogous second part 17.

The lower edge of the first parts 14 and 16 is provided here with a bead 40, while the upper edge of the second parts 15 and 17 is shaped in the form of a complementary gutter 41.

The bead 40 is formed as a continuous ridge, of cylindrical section for example, the diameter whereof is greater than the thickness of the web 14 which bears it, while the gutter 41 is shaped as a groove with converging edges.

Consequently, by clipping the beads 40 into the gutters 41, or by coupling by translation, the different parts are connected together as shown in FIG. 1.

Thanks to this structure, the device can be manufactured, by profile for example, in distinct sub-assemblies, which are subsequently combined. In this fashion, the creep problems encountered with devices already known are avoided.

The closure device illustrated in FIG. 2 is distinguished from the previous one only by the fact that the lower edge of the first parts 14 and 16 is provided with a gutter 40′, while the upper edge of the second parts 15 and 17 is provided with a bead 41′.

Such a closure device can be used, without limitation, to manufacture a sack. To this end, the closure device can be attached to a sheet or sheets constituting the body of the sack or even connect the edges of the webs 15 and 17 opposite the closure profiles 2, 3 to constitute the body of the sack.

FIGS. 3 through 8 will now be referred to in describing embodiments of such a sack and variations of the closure device.

Thus, with reference to FIG. 3, a closure device similar to that of FIG. 1 is attached to a plastic sheet 5 which is folded over itself.

More precisely, two free edges 50 of this sheet 5 are attached to the free ends of the second parts 15, 17 respectively of the two webs 12 and 13, using any attachment means F known to the person skilled in the art, such as an adhesive or a weld.

A sack of a generally known type is then constituted, the closing and opening whereof are accomplished by the cooperation or absence of cooperation of the closure means 2 and 3.

The sack of FIG. 4 has generally a structure analogous to that which was just described with reference to FIG. 3. It is differentiated from it, however, by the fact that the sheet 5 is attached not only to the lower end of parts 15 and 17 of the webs 12 and 13 but also in their upper part, substantially in the vicinity of the closure means 2 and 3.

Better holding and adhesion of the sheet 5 to the closure device is thereby attained, which protecting or making inaccessible the complementary means 4, which makes it impossible to separate them deliberately or accidentally.

In the embodiment of the closure device of FIG. 5A, one is again considering a closure device analogous to that described in FIG. 1.

Here, however, a sheet 6 is used, the ends whereof are shaped in the form of a gutter 41, such that the second parts 15 and 17 of the webs 12 and 13 consist here of the sheet 6 itself.

It suffices then to fold the sheet 6 over itself in a U shape and to engage the gutters 41 of the sheet 6 with the beads 40 of the closure device 1 to constitute a closure device as shown in FIG. 5B.

It will be noted that the closure device illustrated in FIG. 5B has the advantage of having a web portion which connects the webs 12 and 13 and thus constitutes an opening indicator.

Indeed, once this closure device is attached to a sheet or sheets to constitute a sack, it will also be necessary to break this web portion, after separation of the profiles 2 and 3, to gain access for the first time to the contents of the sack. Said web portion also constitutes a seal element for the sack in parallel with the profiles 2 and 3.

As a variation, the manufacture of a sack using only this device is possible if the sheet 6 is of adequate size for such a construction.

The manufacture of a sack by means of a closure device applied to a sheet is clearly illustrated in FIGS. 6 through 8.

Thus, with reference to FIG. 6, at the upper part of the sack there is a closure device 1 to which has been attached a sheet 6 of limited longitudinal extent.

To this sheet 6 another sheet 7 is applied, also folded over itself but of larger size, its opposite free ends 70 being attached by means F (for example adhesive bonding or welding) to the sheet 6 on both its sides.

A sack structure is therefore contemplated which includes, from top to bottom when FIG. 6 is considered, complementary closure means 2 and 3 and an additional closure consisting of the fold in the sheet 6, which must be broken to have access to the inside of the receptacle of the sack (delimited by the sheet 7 itself).

FIGS. 7 and 8 relate to an analogous structure except in that the sheet 7 is attached, at the upper part of the closure device 1 (FIG. 7) and also at the upper part of the closure device 1 and on the opposite faces of the sheet 6 (FIG. 8).

The manufacture in two parts of the closure device thus makes it possible to resolve the problems encountered with earlier devices.

In addition, when it is intended to manufacture a device using two plastics which are incompatible for fabrication by coprofile, one then uses, in conformity with the invention, a first material for the manufacture of the “technical” part 10 of the device and another material for the web 11 of the film. 

1-11. (canceled)
 12. A closure device comprising: two substrate webs; complementary closure means, each being connected respectively to a corresponding web, wherein each web consists of two parts, to with a first part bearing one of the closure means, and a second part distinct from the first, these first and second parts being provided along their lower edge and upper edge respectively with mutual and complementary cooperation means, such as clipping means.
 13. A device according to claim 12, wherein said second parts of said webs are distinct entities.
 14. A device according to claim 12, wherein said second parts of said webs consist of one and the same sheet folded over itself.
 15. A device according to claim 12, wherein said closure means are molded integrally with the corresponding first part.
 16. A device according to claim 12, wherein said closure means are inserted elements.
 17. A device according to claim 12, wherein said closure means are complementary profiles.
 18. A device according to claim 12, wherein said mutual cooperation means consist of complementary beads and gutters.
 19. A device according to claim 12, wherein said first and second parts are made of different plastics, incompatible in profile.
 20. A sack manufactured using a closure device comprising: two substrate webs; complementary closure means, each being connected respectively to a corresponding web, wherein each web consists of two parts, to with a first part bearing one of the closure means, and a second part distinct from the first, these first and second parts being provided along their lower edge and upper edge respectively with mutual and complementary cooperation means, such as clipping means.
 21. A sack according to claim 20, wherein said second parts of said webs themselves delimit the receptacle of this sack.
 22. A sack according to claim 20, which includes at least one additional web attached to said first parts and/or second parts which delimits the receptacle of the sack. 